SERS or Surface Enhanced Raman Scattering is a technique used to increase the sensitivity of Raman spectroscopy. Using this method scientists can potentially examine single molecules absorbed on a metal surface. However they do not fully understand the mechanisms behind this increased sensitivity and so are exploring theories as to how and why this is occurring.

HRS600 Stage on the Raman Spectrometer

Dr Sharath Sriram from RMIT University Australia and a team of scientists are using an HFS91-PB4 (HFS600) Linkam stage to apply a oscillating electrical field to a sample of thiophenol and study the corresponding effect on the SERS spectra. To apply this field micro-fabricated, silver nano-textured electrodes are used within the stage. These were functionalized by application of a mono-layer of thiophenol. The SERS measurements were obtained using a 532nm laser with a 50second accumulation time.

Close up of Dr Sharath Sriram Stage with electrodes

The team have found that applying the oscillating field appears to rearrange these molecules and allow specific bonds to be identified. These bonds' peak intensities may be modified by applying an electrical field which could potentially allow the team to increase or suppress areas of interest. (Theoretically they could dial-in to an area of interest in the same way you or I would tune in to a favoured radio channel). The scientists are continuing to investigate the application of this technique to study separate analytes and bonds.